Air conditioning system

ABSTRACT

An air conditioning system for use with recreational vehicles and the like includes a single fan motor for driving a condenser fan to force outside air over the condenser coil and an evaporator fan to force room air over the evaporator coil for cooling the room air. A damper is positioned to control the volume of room air moved by the evaporator fan. Thus, whether the system is adjusted for maximum reduction of sensible temperature, maximum removal of latent heat, or any intermediate combination, the operating conditions for the condenser coil are at or near optimum. In a preferred embodiment, control of the damper position is effected by the same knob which actuates a switch to supply current to the fan motor and to the compressor motor so that the damper is automatically positioned as the system is set up for various possible operating conditions.

United States Patent Nagele et al.

AIR CONDITIONING SYSTEM Inventors: Immanuel P. Nagele, Valley Center;

Jerald W. Blakely; Lloyd B. Vandeventer, both of Wichita, all of Kans.

[73] Assignee: The Coleman Company, Inc.,

Wichita, Kans.

[22] Filed: Feb. 19, 1974 1211 Appl. No.: 443,491

[52] U.S. Cl. 62/408; 62/262; 62/267 [51] Int. Cl. F25D 17/04 [58] Field of Search 62/408, 262, 267

[56] References Cited UNITED STATES PATENTS 2,166,813 7/1939 Gibson 62/180 2,477,351 7/1949 Spofford 62/180 2,549,547 4/1951 Trask i 62/262 2,656,685 10/1953 Borgerd.. 62/186 2,715,324 8/1955 Rose 62/262 2,780,929 2/1957 Roseman 62/408 2,811,022 10/1957 Lathrop 62/262 2,908,147 10/1959 Powers... 62/408 3,306,645 2/1967 Maleck 62/262 3,733,843 5/1973 MacLeod 62/262 Primary ExaminerWilliam .1. Wye Attorney, Agent, or Firm-Dawson, Tilton, Fallon & Lungmus [57] ABSTRACT An air conditioning system for use with recreational vehicles and the like includes a single fan motor for driving a condenser fan to force outside air over the condenser coil and an evaporator fan to force room air over the evaporator coil for cooling the room air. A damper is positioned to control the volume of room air moved by the evaporator fan. Thus, whether the system is adjusted for maximum reduction of sensible temperature, maximum removal of latent heat, or any intermediate combination, the operating conditions for the condenser coil are at or near optimum. In a preferred embodiment, control of the damper position is effected by the same knob which actuates a switch to supply current to the fan motor and t0 the compressor motor so that the damper is automatically positioned as the system is set up for various possible operating conditions.

5 Claims, 5 Drawing Figures PATENTED 3-, 896,634

SHEET 2 u m, X

AIR CONDITIONING SYSTEM BACKGROUND AND SUMMARY The present invention relates to air conditioning systems; and more particularly, it is concerned with air conditioning systems of the type which are used on recreational vehicles, and the like. Typically, such systems include an electrical motor compressor or pump which takes a refrigerant from a suction line and compresses it to a heated gas which is then routed through a condenser coil where a condenser fan forces outside air over the condenser coil to cool the gas and cause it to become a liquid.

The liquid refrigerant is then fed through a metering device, such as a capillary tube, to an evaporator coil located inside the vehicle. The liquid expands in the evaporator coil, thereby cooling the coil. lnside or room air is circulated over the evaporator coil by an evaporator fan which is normally a blower fan or squirrel cage fan.

ln systems of this type, it has been desirable to provide two or more different speeds of operation for varying the quantity of air supplied to the evaporator. Further, it is conventional practice to use an electrical fan motor with a double-ended shaft. One shaft end drives the condensor fan for circulating outside air'over the condenser coil, and the other shaft end drives the evaporator fan or blower. In order to achieve the different operating speeds, the fan motor is a multi-speed motor.

The compressor motor is left to operate at the same speed regardless of the fan motor speed. The system is normally designed for greatest cooling capacity at the higher speed for the fan motor. In this manner, the greatest volume of outside air is forced over the condenser coil at the same time as there is maximum circulation of room air.

ln a multi-speed system of this type, the change in speed in the fan motor may be accomplished by providing multiple speed taps from the motor windings, one for each speed. Systems have also been provided with a solid state motor control circuit which changes the speed of the fan motor over a continuous range in a stepless manner.

In applications with a single motor driving both the room air blower wheel for the evaporator coil and the propeller fan for the condenser coil. if the fan motor speed is lowered to reduce the volume of room air being circulated, the condenser fan is also slowed down. thereby decreasing the amount of air forced over the condenser coil and reducing cooling of the refrigerant in the condenser coil.

In the past, when the condenser fan speed is lowered. system performance characteristics have deteriorated significantly. For example, when the total volume of air forced over the condenser is reduced, the condenser operates at a higher temperature, and this results in higher head pressures for the compressor, reducing its efficiency. Further, unevaporated liquid refrigerant may pass through the evaporator coil and enter the suction side of the compressor in slugs. thereby causing vibrations as the liquid is fed through the compressor. The greater head pressures on the compressor result in drawing higher current for the compressor. This, together with the loading conditions on the fan motor and the hotter condenser air cause the fan motor and comthe lifetime of both.

It is possible to avoid these undesirable characteristics by using a constant speed motorfor the condenser fan and a separate evaporator blower motor of the multiple speed type. However, this solution increases the initial costs substantially. and it also increases the operating costs and potential shut-downs because three separate motors (one for the compressor, one for the condenser fan and one for the evaporator fan) are all operated off of a single circuit.

The present invention uses a single constant speed fan motor driving both the condenser fan and the evaporator blower. A damper is incorporated in the system to adjust the volume of air forced by the evaporator fan over the evaporator coil. Thus, there is continuous adjustment of the volume of room air being cooled over a wide range of volumes. Further, as the volume or recirculating room air is reduced or starved by the damper, it will tend to unload the blower wheel and thus reduce the load on the fan motor, due to the characteristics of a squirrel cage blower. This results in a slight increase in the fan motor speed and thus an increase in the amount of air being forced through the condenser coil. For example, the fan motor operating at i570 RPM at maximum load anddelivering a maximum volume of air through the evaporator coil will increase in speed to 1660 RPM as the recirculating room air is dampened and the fan motor, is partially unloaded. 1

When the condenser fan operates at a higher speed, the refrigerant system operates more efficiently because with the delivery ofa greater volume of air to the condenser, its temperature and corresponding head pressure are reduced,.thus the compressor work is reduced: and the likelihood of slugs of liquid refrigerant reaching the compressor is also reduced.

When the damper is set for maximum delivery of recirculating room air, there is achieved maximum cooling in the sense of reducing the sensible temperature of the room, whether it is a vehicle or not. In this context sensible" heat refers to, the measurable difference in temperature. Latent heat refers to the heat present in an atmosphere of high humidity.

In a recreational vehicle, motor home or mobile home, where cooking and washing take place within the room enclosure of the vehicle, it is highly desirable to have an air conditioning system which is efficient in reducing the sensible temperature as well as in removing moisture from the room, depending upon the conditions. For example, if the outside ambient temperature is quite hot, obviously it is desirable to have maximum sensible temperature change within the vehicle. On the other hand, it may be-the case that although the outside ambient temperature is cool, nevertheless, the temperature within the vehicle may be uncomfortably warm due to the suns beating down on the vehicle or to high humidity inside the vehicle. In this case a comfortable temperature can be reached by removing moisture or latent heat from the air within the vehicle. In either case, the quantity of heat removed from the vehicle may be substantially the same because the amount of heat that must be removed to condensewater vapor is substantially greater than that which is required to reduce the temperature of a lower humidity air.

- In prior art systems using a single fan motor driving both the condenser fan and the evaporator fan, as has been mentioned. it has been the practice to design the system for maximum efficiency during reduction of the sensible temperature when a maximum amount of room air is being recirculated. If the speed of the fan motor is then reduced. the amount of room air being recirculated is reduced, but so is the amount of air forced through the condenser coil. Thus, the systems ability to remove latent heat is substantially diminished from that which accompanies maximum condenser air flow.

With the present invention, when the amount of recirculating room air is reduced by the damper, the fan motorspeeds up slightly, thereby increasing the cooling of the gas in the condenser and decreasing the temperature of the evaporator coil to enhance the removal of latent heat.

In a preferred embodiment, the damper is controlled by means ofa push-pull cable assembly having a center wire attached to the shaft of a switch which operates the fan motor and the compressor motor. In the OFF position, both motors are off, and the damper is fully closed. If the damper is installed in a return or supply air conduit, it prevents a cold down-draft from the room air conduit during cold weather. It will be appreciated that air conditioning units of this type are normally installed on the roof of a recreational vehicle or the like; and heat may be lost through the metal walls of the room air conduit, thereby permitting cold air to accumulate in the room air conduit. This cold air may then cause a downdraft, but by installing the damper of the present invention in the supply or return air opening, this down-draft is prevented. Further, when the vehicle is moving there may be a ram effect of the outside air'against the condenser propeller fan; and because the condenser fan is connected to the same shaft as the evaporator fan, the evaporator fan is driven under this ram of air effect. This also has a tendency to create drafts by circulating room air; and with the present invention, when the operating switch is in the OFF position, the damper closes the room air return and prevents recirculating of room air.

There are other features and advantages to the present invention, but these are best understood in connection with the following detailed description accompanied by the attached drawing wherein identical reference numerals will refer to like parts in the various views.

THE DRAWING FIG. I is a schematic diagram of an air conditioning system incorporating the present invention;

FIG. 2 is a partially broken-away vertical cross sectional view of an air conditioning system showing the control panel and return air section, including damper;

FIG. 3 is a frontal view ofa control panel for the present invention;

FIG. 4 is a fragmentary cross sectional view taken through the sight line 44 of FIG. 3; and

FIG. 5 is atop view of the switch and cable assembly as seen in FIG. 4. with a portion of the switch removed for clarity.

DETAILED DESCRIPTION Referring first to FIG. I, there is shown in diagrammatic form an air conditioning system including a compressor motor 10, a'fan motor 11. a condenser coil generally designated 12 and an evaporator coil generally designated 13. The fan motor II is provided with a double-ended shaft 15 to one end of which is attached a propeller-type fan 16 for forcing outside air over the condenser coil 12. This is sometimes referred to as the condenser fan.

At the other end of the shaft I5, and within an enclosure separate from the outside air, is a squirrel cage fan 17 which is used to draw room air over the evaporator coil 13 for cooling it.

The compressor 10 takes a refrigerant from a suction side 20 and compresses it, forcing it in the direction of the arrow 21 through a line 22 into the condenser coil 12. The condenser fan 16 cools the coil 12 with outside air. causing the refrigerant to cool and form a liquid which exits the condenser coil 12 and is fed to a metering device 23 at the inlet of the evaporator coil 13. The liquid refrigerant starts to vaporize at the metering device 23 which may be a capillary tube, thereby absorbing heat and cooling the surface of the evaporator coil 13.

It will be appreciated that the illustration of FIG. I is only schematic and does not necessarily represent the relative positions of the various elements, and that such details are not necessary for a complete understanding of the invention.

In FIG. I, then, the flow of recirculating room air is indicated by the arrow 25, forced by the blower 17. The recirculating room air flows through a movable damper assembly generally designated 26. The structure and operation of the damper assembly 26 will be more fully explained below. It will be appreciated however, that the damper assembly 26 is actuated to control the flow of recirculating room air across the evaporator coil 13; and in the preferred embodiment, the damper assembly 26 is located at the return air inlet op ening-- as distinguished from the discharge air outlet opening. It will also be appreciated that various conduit systems may be used to distribute the recirculating room air throughout the vehicle. and that the damper may be located in the discharge outlet, depending upon the application.

Turning now to FIG. 2, reference numeral 15 again designates one end of a double-ended shaft driven by a fan motor (not shown) which is a single speed motor. A blower wheel 17 is mounted to one end of the shaft 15 within a blower scroll designated 30 having an air intake aperture 3] and a discharge aperture 32. The discharge aperture 32 forms a discharge opening for recirculating room air into a duct system or distribution baffle, depending upon the application.

In the illustrated embodiment, the air conditioning system is designed for location on the room ofa recreation vehicle or the like wherein the roof is partially shown at 33. The system includes a cover 34.

The return air is drawn in through a return air inlet opening generally designated by reference numeral 37; and at this inlet there is located the baffle assembly 26. After being drawn in at the opening 37, in an amount depending upon the positioning of the baffle assembly as will be described, the return air flows through the evaporator coil 13 and thence into the inlet opening 31 of the evaporator fan 17. A drip pan 38 may be provided beneath the evaporator coil 13 as is generally known, for collecting condensed moisture.

Turning now to the baffle assembly 26, it includes a baffle plate 40 which has sufficient length and breadth to completely enclose the return air inlet opening 37. The lower end of the plate 40 is bent as at 4! and welded to a transverse shaft 42 about which it rotates.

The shaft 42 is mounted at each side in a pivot bracket (not shown). Attached to one end of the damper plate at the pivot shaft 42 is a control connector bracket 43 in the shape of an L and having an aperture 44 adjacent to the toe of the base of the L.

As the control connector bracket is pivoted from the three positions shown respectively at 45a, to 451) and then to 450. the damper plate 40 will assume respec tively the three positions designated as A (fully closed). B (fully open) to C (maximum removal of latent heat). There are, of course, a continuum of positions in between those illustrated. The position shown at C is a limit position at which the stop is provided by the control mechanism presently to be described.

The return air inlet opening extends from the flange designated 47 to the flange designated 48; and will be entirely covered when the damper plate is in closed position.

The damper assembly 26 is controlled by the position ofa rotary switch generally designated by reference numeral 50 in FIG. 4 and including a shaft 51 having a flat 52. Mounted to the distal end of the shaft 51 is a control knob 53. The switch 50 is mounted to a control panel faceplate 54 by means of a bracket 55; and it forms part of a control panel assembly generally designated by reference numeral 58 in FIGS. 2 and 3.

In FIG. 2 the control panel assembly 58 is shown without the control knobs in order to better illustrate the structure and functioning of the damper assembly.

A J-shaped switch lever bracket is designated by reference numeral 60 in FIG. 4, and it includes an apertured upper portion 61, a base portion 62 and a lower portion 63. The upper and lower portions 61, 63 have apertures for fitting over the shaft 51 of the switch 50; and a set screw 64 is threaded into the base portion 62 and forced against the flat 52 of the shaft 51 to secure the switch lever bracket to the shaft of the switch 50 and to position it properly. At the distal end of the upper portion 61 of the bracket 60 there is another aperture which receives the distal end of a wire 65 which is slidably fltted into an armored jacket 66 to form a push-pull cable assembly generally designated by reference numeral 70.

As best seen in FIGS. 2, 4 and 5, the cable assembly 70 is secured to the control panel assembly 58 by means of a bracket 72 fastened at 73 to the control panel. The bracket 72 includes a sleeve 74 frictionally engaging the armored jacket 66 of the cable assembly 70, and an inclined or ramp portion 75 located between the sleeve 74 and the connection to the switch lever bracket 61. The ramp 75 is braced against a wall of the control panel by means of a leg portion 76; and the ramp 75 is formed to direct the axis of the cable 65 to intersect approximately with the axis of the shaft 51 of the switch 50. It will be appreciatedthat these two axes extend in perpendicular directions, and that the end portion of the cable assembly 70 is free to permit a certain amount of lateral play as the bracket 60 is rotated.

Turning now to FIG. 5 in particular. the shaft 51 of the rotary switch 50 is positioned in the OFF position. the bracket 60 is in the position shown. Turning for a moment to FIG. 3. from the OFF position. the switch knob 53 is rotatable only in a clockwise direction (counterclockwise in FIG. 5 because it is a rear view). With the switch 50 in the OFF position, the axis of the cable 65 lies along the dotted line 78 and is connected to the bracket 60 as represented by the smaller circle designated 80. As the knob 53 is turned, the bracket 60 rotates counterclockwise in FIG. 5 and the locus of the connection 80 between the bracket 60 and the cable 65 is about the larger circle designated 81.

The switch 50 is provided with two sets of contacts, one for energizing the fan motor and the other for supplying energy to the compressor motor. In each position, there is an extended swell period for operating the contacts-- that is, the shaft 51 may be rotated through a fairly wide angle while maintaining the switch contacts in a closed position. This is done in a conventional manner by means of a cam actuator which closes the contacts when the shaft 51 is in certain angular positions. The system areas of operation are shown in FIG. 2. The area designated 82 is one wherein the fan motor only is energized; and the area 83 is one wherein the fan motor and the compressor motor are both energized. Once the knob 53 is turned from the OFF position to actuate the fan motor contacts, beginning at the position designated 82a in FIG. 2, the fan motor remains energized for all subsequent positions of the switch in a clockwise direction (when referring to FIG. 2). On the faceplate of the control panel 58 there is a corresponding area indicated by 82b wherein only the fan is operating to recirculate room air. However. as mentioned, the fan motor is energized for subsequent positions of the switch knob 53 to maintain the supply of energy to the motor which drives the condenser fan and the evaporator blower 17. Located between the FAN ONLY" range and the COOLING range designated 83 there is a detent provided in the switch 50 so that in adjusting the system one does not inadvertently turn on the compressor; and this detent is located to momentarily stop the rotation of the shaft 51 when the connection is in the position designated B in FIGS. 2 and 5. At this time, of course. the fan motor is still energized.

It will be appreciated that as the switch is rotated clockwise in FIG. 2 (counterclockwise in FIG. 5) from the position A to the position 8', the connector point for the end of the cable 65 is moved correspondingly. and the cable is moved into the armored jacket 66 to rotate the cable connector bracket 43 in FIG. 2 from the position shown at 4541 to that shown at 45b, thereby rotating the damper plate 40 counterclockwise from the closed position shown at A to the fully open position shown at B. Thus, the region of the rotary switch represented by the area 82 represents a continuous adjustment of the amount of room air that can be recirculated by the evaporator blower 17. It will also be appreciated that when the switch is in the OFF position, the damper plate 40 completely closes the return air inlet opening 37 so that any cold air that may be collected in the plenum defined by the cover 34 will not be permitted to cause a downdraft.

Continuing with the operation. then, as the knob 53 is rotated still further clockwise (FIGS. 2 and 3) from the detent position, the compressor is turned on while the fan motor is continued to be energized. At this position. sensible cooling is at a maximum because the damper 26 is in the fully-open position. thereby permitting maximum flow of recirculating room air through the evaporator 13.

Referring again to FIGS. 2 and 5. as the knob 53 is further turned away from the detent position. the connection of the end of the cable 65 to the switch lever bracket 60 moves from the position 8' to C'. thereby drawing the cable 65 out of the jacket 66, and, hence. rotating the damper control connector 53 in a clockwise position to that shown at In terms of the area 83, the compressor is turned on at the position 83a, and maximum cooling for reducing sensible temperature is achieved. As the damper is closed, the fan motor speed increases slightly and the compressor continues to operate, thereby cooling the temperature of the evaporator coil 13 and achieving greater capacity for removal of latent heat or humidity. At the location C for the switch, there is a stop which prevents further turning of the switch and limits the final position of the damper plate 40 to that shown at the corresponding C position in FIG. 2. This position of the damper plate 40 is selected so that a minimum amount of return air is circulated through the evaporator coil 13 and prevents freeze-up.

Also located on the control panel assembly 58 is a temperature control knob 90 (see FIG. 3) which adjusts the setting of a thermostatic switch to preset the temperature at which the compressor is turned on and off, as is commonly done in conventional systems.

To summarize the operation briefly, then, when the rotary control switch is in the OFF position, the damper plate 40 is in a position to fully close the return air inlet opening 37. This prevents downdrafts of cold air, and it further prevents undesired recirculation of room air.

When it is desired to use the air conditioning system. the knob 53 is turned clockwise in FIG. 3 (it is prevented from being turned counterclockwise from the OFF position), and the fan motor starts. While the knob 53 is being turned, however, the shaft 51 rotates the actuating lever to push the wire 61 into the armored cable 66, thereby rotating the damper connector bracket 43 and damper plate 40 in a counterclockwise position in FIG. 2 to open the return air inlet opening. While the fan motor is still energized, the knob 53 may be further turned until the damper is fully opened, represented by the position B.

The rotary switch then encounters a detent to prevent accidental turning on of the compressor while the fan only control is in maximum position. Further turning of the knob 53 will energize the compressor while the fan motor continues to run; and this is considered to be an advantage in that when the compressor is started, a maximum flow of air through the return air conduit has already been attained and the starting current load is reduced by having the fan motor energized prior to the compressor motor rather than by simultaneously energizing both.

At this position, then, with the damper fully opened, a maximum cooling effect for reducing sensible temperature is achieved, and the maximum amount of air is circulated by the room air blower through the evaporator coil 13.

As the knob 53 is further turned clockwise in FIG. 3, the end connection of the wire 65 will be rotated coun terclockwise in FIG. 5 from position B to C. thereby rotating the damper plate 40 clockwise in FIG. 2 between the correspondingly designated positions. At position C', the flow of room air is substantially reduced, thereby removing some of the load from the blower 17. This will cause the fan motor to speed up slightly and increase the flow of air over the condenser coil I2 for better cooling. This, in turn, will reduce the head pressure on the compressor I0 and cool the evaporator coil 13 for better removal of latent heat from the recirculating room air.

The system just described greatly facilitates readjustment of the damper. as needed to obtain optimum damper operation. Referring to FIG. 2, a clamp 98 is secured to a wall 99 by means of a clamp screw. This screw (not shown) is loosened, and this permits the cable assembly to move freely in an axial direction. With the rotary switch knob 53 in the OFF position, the cable assembly is adjusted relative to the clamp 98 until the damper plate 40 fully closes the return air opening 37. Thus positioned, the clamp 98 is again secured to the wall 99 by means of the screw, and readjustment is completed.

Having thus disclosed in detail a preferred embodiment of the invention, persons skilled in the art will be able to modify certain of the structure which has been disclosed and to substitute equivalent elements for those described while continuing to practice the principle of the invention, and it is, therefore, intended that all such modifications and substitutions be covered as they are embraced within the spirit and scope of the appended claims.

We claim:

I. In an air conditioning system including a compressor for compressing a refrigerant, a condenser receiving refrigerant from the compressor and an evaporator receiving liquid refrigerant from the condenser and feeding gaseous refrigerant back to the compressor, the combination comprising: a fan motor provided with a shaft; a first condenser fan mounted to said shaft for forcing outside air over said condenser: a second evaporator fan mounted to said shaft for forcing room air over said evaporator through a room air conduit. and settable damper assembly means, a plate; and mounting means for said plate for selectively positioning said plate relative to said room air conduit between a fully closed position and an open position, said control means comprising mechanical link means including a flexible link connected at one end of said damper plate. a jacket slidably receiving said flexible link; first clamp means for anchoring said jacket adjacent said damper plate; a control switch for operating said fan motor and said compressor motor; second clamp means for fastening said jacket adjacent said switch, said second clamp means including a ramp for directing said-link such that the axis thereof intersects with the rotatable shaft of said switch; has been inserted, the other end of said link being connected to said control switch and movable therewith in response to the turning on of said fan motor and said compressor motor, said link being actuatable to position said damper plate in the fully closed position to seal against the passage of room air through said room air conduit when said system is turned off and to move said plate through a continuous range of open positions in the FAN ONLY state between said closed position and said fully open position, said control switch being further actuatable to energize the compressor when said damper plate is in the fully open position with fan motor energized and being further actuatable to move said damper plate through a continuous range of positions to a relatively closed position while maintaining said compressor and said fan motor energized; whereby as said plate is moved between said relatively open position and said relativelyclosed position while said compressor is operating. the flow of air through said room air conduit is reduced, and the load on said fan motor is diminished. thereby increasing the speed of said fan motor and providing a greater flow of outside air to said condenser.

2. ln an air conditioning system including a compressor for compressing a refrigerant. a condenser receiving refrigerant from a compressor and an evaporator receiving liquid refrigerant from the condenser and feeding said refrigerant back to the compressor the combination comprising; a fan motor having a single shaft extending therethrough to provide a first and second end; means providing a return air passage for recirculating air within a confined space. said evaporator coil being located within said return air passage; a condenser fan mounted to one end of said shaft for forcing outside air over said condenser to cool the same; an evaporator fan mounted to the other end of said shaft for forcing recirculating air over said evaporator coil through said return air passage; damper assembly means controllable by a person and including a movable damper means for regulating the flow of air through said return air passage; and control means including a switch for actuating said compressor and said fan motor while controlling the position of said damper means: a cable assembly having an outer fixed jacket and a slidable wire therein connected between said damper means and said switch, whereby the position of said switch further controls the position of said damper means; said switch including an off position and is movable therefrom in a given direction to sequence the operation of said system including first turning on said fan motor and then turning on said compressor while said fan motor is continuously energized; said cable assembly means being adapted to hold said damper means to close said return air passage when said switch is in said off position and to continuously vary the opening in said return air passage as defined by said damper means as the position of the switch is changed.

3. The system of claim 2 wherein said switch is a rotary switch and further includes a momentary stop just prior to turning on the compressor and a positive stop prior to closure of damper.

4. The system of claim 3 wherein said switch is adapted to energize said fan motor over an extended period of angular movement to vary the position of said damper means while operating in the fan-only mode for adjusting the volume of air through said return air passage.

5. The system of claim 2 wherein said switch is further adapted to operate said compressor and said fan motor over an extended angular displacement of said switch while continuing to adjust the position of said damper means from a fully open position to a relatively closed position permitting a minimum amount of air to flow through said return air passage.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. Dated lnventofls) Immanuel P. Nagele, Jerald W. Blakely and Lloyd B.

Vandeventer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In claim 1 column 8 line 48 delete the phrase "has been inserted,"

Signed and Scaled this fourteenth Day Of October 1975 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner of Patents and Tr zdemarks 

1. In an air conditioning system including a compressor for compressing a refrigerant, a condenser receiving refrigerant from the compressor and an evaporator receiving liquid refrigerant from the condenser and feeding gaseous refrigerant back to the compressor, the combination comprising: a fan motor provided with a shaft; a first condenser fan mounted to said shaft for forcing outside air over said condenser; a second evaporator fan mounted to said shaft for forcing room air over said evaporator through a room air conduit; and settable damper assembly means, a plate; and mounting means for said plate for selectively positioning said plate relative to said room air conduit between a fully closed position and an open position, said control means comprising mechanical link means including a flexible link connected at one end of said damper plate; a jacket slidably receiving said flexible link; first clamp means for anchoring said jacket adjacent said damper plate; a control switch for operating said fan motor and said compressor motor; second clamp means for fastening said jacket adjacent said switch, said second clamp means including a ramp for directing said link such that the axis thereof intersects with the rotatable shaft of said switch; has been inserted, the other end of said link being connected to said control switch and movable therewith in response to the turning on of said fan motor and said compressor motor, said link being actuatable to position said damper plate in the fully closed position to seal against the passage of room air through said room air conduit when said system is turned off and to move said plate through a continuous range of open positions in the ''''FAN ONLY'''' state between said closed position and said fully open position, said control switch being further actuatable to energize the compressor when said damper plate is in the fully open position with fan motor energized and being further actuatable to move said damper plate through a continuous range of positions to a relatively closed position while maintaining said compressor and said fan motor energized; whereby as said plate is moved between said relatively open position and said relatively closed position while said compressor is operating, the flow of air through said room air conduit is reduced, and the load on said fan motor is diminished, thereby increasing the speed of said fan motor and providing a greater flow of outside air to said condenser.
 2. In an air conditioning system including a compressor for compressing a refrigerant, a condenser receiving refrigerant from a compressor and an evaporator receiving liquid refrigerant from the condenser and feeding said refrigerant back to the compressor, the combination comprising: a fan motor having a single shaft extending therethrough to provide a first and second end; means providing a return air passage for recirculating air within a confined space, said evaporator coil being located within said return air passage; a condenser fan mounted to one end of said shaft for forcing outside air over said condenser to cool the same; an evaporator fan mounted to the other end of said shaft for forcing recirculating air over said evaporator coil through said return air passage; damper assembly means controllable by a person and including a movable damper means for regulating the flow of air through said return air passage; and control means including a switch for actuating said compressor and said fan motor while controlling the position of said damper means; a cable assembly having an outer fixed jacket and a slidable wire therein connected between said damper means and said switch, whereby the position of said switch further controls the position of said damper means; said switch including an off position and is movable therefrom in a given direction to sequence the operation of said system including first turning on said fan motor and then turning on said compressor while said fan motor is continuously energized; said cable assembly means being adapted to hold said damper means to close said return air passage when said switch is in said off position and to continuously vary the opening in said return air passage as defined by said damper means as the position of the switch is changed.
 3. The system of claim 2 wherein said switch is a rotary switch and further includes a momentary stop just prior to turning on the compressor and a positive stop prior to closure of damper.
 4. The system of claim 3 wherein said switch is adapted to energize said fan motor over an extended period of angular movement to vary the position of said damper means while operating in the fan-only mode for adjusting the volume of air through said return air passage.
 5. The system of claim 2 wherein said switch is further adapted to operate said compressor and said fan motor over an extended angular dispLacement of said switch while continuing to adjust the position of said damper means from a fully open position to a relatively closed position permitting a minimum amount of air to flow through said return air passage. 